The present invention relates to a massage system for a vehicle seat comprising a plurality of inflatable air cells arranged in a series of subsequent air cells, a supply line structure having a connection for fluid communication from and to each of the plurality of air cells in said series, a pump for supplying air under pressure to the supply line structure, a control or switch unit for controlling the operation of the pump, venting means for venting the supply line structure, means for controlling air flow to and from the air cells to provide a sequential inflation/deflation along said series of air cells.
Drivers and passengers of motor vehicles, especially when driving long distances, often experience discomforts caused by long time static posture when seated in a vehicle seat. This is not only felt as being uncomfortable and causing for example back pain but may also lead to permanent impairment of health, in particular for professional drivers such as taxi, truck and bus drivers. To provide a remedy the automotive industry for some time has offered vehicle seats with integrated massage systems in the seat back.
Such a massage system is for example disclosed in U.S. Pat. No. 5,135,282 A. A series of inflatable air cells is disposed along the seat back close to the inner surface of the seat back cover. A supply line structure is receiving compressed air from a pump and is supplying this compressed air to the air cells for sequentially inflating/deflating the series of air cells. For this purpose the supply line structure comprises a common supply line interconnecting the air cells in series, and an exhaust or venting line interconnecting the series of air cells, which venting line is capable of being opened to the environment for venting in order to deflate the air cells. In order to produce a propagating sequential inflation along said series of the air cells starting from the first cell at the lower end of the seat back and continuing cell by cell to the last cell at the upper end of the seat back, a number of controllable valves and a control unit are provided. In particular, there is a valve at the beginning of the supply line upstream of the first cell, and a controllable valve between each pair of adjacent cells along said series of air cells. In order to initiate an inflation cycle the control or switch unit starts the pump to deliver air and opens the first valve in the supply line upstream of the first air cell while keeping the remaining valves in a closed state such that the first cell is inflated. The control unit is arranged to open the remaining valves along said series of air cells sequentially such that, after the first air cell has been inflated, the valve upstream of the second air cell is opened to inflate the second air cell, thereafter the valve upstream of the third cell is opened etc. until all air cells along said series of air cells are inflated. After all air cells of said series of air cells have been inflated the control unit stops the pump and the venting line in a corresponding manner sequentially to deflate the air cells in said series of air cells in sequence, again starting with the first air cell, and proceeding continuously by cell through that series of air cells until all cells are deflated.
This massage system for a vehicle seat is rather complicated because of the rather large number of controllable valves, namely 2n+2 valves for a series of n air cells. This implies rather high costs for the valves themselves and for the rather complicated assembly process including the provision of a connection between each of the valves and the control unit.